\begin{tikzpicture}
    \tkzDefPoints{0/0/A, 3/0/B, 4/2/C, 1/2/D}
    \tkzDefPointOnLine[pos=0.5](A,D)  \tkzGetPoint{E}
    \tkzDefPointOnLine[pos=0.3](A,B)  \tkzGetPoint{F}

    \tkzDrawPolygon(A,B,C,D)
    \tkzDrawSegments(B,E  E,C  C,F  F,D)
    \tkzLabelPoints[above](C,D)
    \tkzLabelPoints[below](A,B,F)
    \tkzLabelPoints[left](E)
\end{tikzpicture}

